1. Field of the Invention
The present invention relates to a driving device for opening/closing a sunroof of an automobile, more particularly, technologies which can be applied effectively to a sunroof driving device having a manual opening/closing mechanism.
2. Description of the Related Art
Conventionally in a vehicle with a sunroof thereon, an opening is provided in a roof so that in this opening a roof panel formed by a roof material such as a steel plate or a glass material is arranged in a sliding manner. In this case, guide rails are provided at both edges of the opening, and shoes are mounted so as to slide along the guide rails. A roof panel and an end of a driving cable are fixed to the shoes. With this, by pushing/pulling the driving cable with an electric motor, opening/closing of the roof panel can be performed within the opening.
An armature shaft of the electric motor (hereinafter abbreviated as motor) is provided with a worm gear, and a worm wheel gear is arranged so as to mesh with the worm gear. The worm wheel gear is provided with an output shaft via a clutch mechanism such as a friction clutch. This clutch mechanism reduces cut-off torque and also prevents damage of the meshing portion with the worm gear in case of that the worm wheel gear is rotated during manual operation. The output shaft is provided with a driving gear, with which a driving cable is engaged, so that, by driving the motor, the driving cable is pushed and pulled, thus the roof panel is moved.
The full-closed and full-opened positions of the roof panel are both determined by a detection switch such as a limit switch. Japanese Patent Publication No. 61-46027 and Japanese Patent Publication No. 4-40213 disclose therein a configuration for turning this limit switch ON/OFF by using a certain type of K-H-V (S-C-P) planetary gear mechanism, so-called drunken gear mechanism. That is, the output shaft is provided with an eccentric external gear, to the outside of which is combined an internal gear having a more large number of gear teeth than the eccentric gear. On the outer periphery of the internal gear is formed a cam in such a configuration that the cam may contact with the limit switch according to the turning angle of the output shaft. With this, when the output shaft turns by a predetermined angle, the external gear slides accordingly, thus causing the internal gear to rotate by as much as a difference in the number of gear teeth between the two gears. Therefore, when the output shaft rotates by a predetermined number of revolutions, the cam crest moves to turn the limit switch ON/OFF, thus controlling the motor. Also, when the roof panel has to be tilted, it can be controlled in its tilt-up operation by appropriately changing the cam shape, the number of the limit switches, the switch configuration, and the like.
A configuration for detecting the position of the roof panel on the side of the output shaft is suggested also in Japanese Utility Model Laid-open No. 2-23216. By this utility model, on the side of the output shaft, an idle gear for detection is provided besides a driving device and has a cam formed thereon. With this, this cam is used to operate the limit switch, to detect the rotational position of the output shaft. Alternatively, there is given another configuration using an intermittent gear in place of the cam, where an intermittent gear is provided on the side of the output shaft besides the drive gear for detecting the position.
Further, recently, besides simple opening/closing operations, fine control is conducted such as full-opening/full-closing or tilting by one-shot operation or reverse driving of the roof panel in the case of catching-in of foreign materials. Such fine control has to be conducted such that the roof panel is not only opened or closed fully but also its current position is sensed in opening/closing. With this, in addition to the roof-panel position detection by use of the drunken gear mechanism, and the like, pulse control is also conducted by means of motor rotational detection.
In this case, to improve the accuracy of the pulse control, an armature shaft which has more large number of revolutions than other means among the driving devices is utilized to obtain pulses in such a way, for example, that the armature shaft is provided with a magnet to detect its proximity by a sensor such as a Hall IC, thus obtaining controlling pulses. With this, the limit switch signal and the pulse count are used to obtain the current position of the roof panel, to enable fine control based on the position of the roof panel. Also, when the number of motor revolutions dropped rapidly at a position other than the full-opened and full-closed positions, it is assumed that catching has occurred and, for example, such a control as reverse rotation of a motor can be performed.
On the other hand, in said sunroof and the like, if the roof panel cannot be opened or closed due to a failure of the motor or any other driving mechanism, the roof panel can be opened or closed manually as an emergency operation. For example, according to said Japanese Patent Publication No. 4-40213, in emergency, a tool is inserted into the shaft for manual operation, to enable manual opening/closing of the roof panel. That is, when the tool is inserted into the manual-operation shaft and pressed upward, the connection is cut off between the motor and the driving device to enable rotation only of the gear by the tool, in order to easily open or close the roof panel.
An opening/closing driving device according to such a configuration, however, has on the output shaft side an idle gear, an intermittent gear, a manual-operation shaft, and the like, besides the output shaft. As the result of this arrangement, there is a drawback that the gear configuration is too complicated with an increased projection area thereof to satisfy the requirements for miniaturization and light weight. Also, as the number of parts become numerous, there is another that the steps for assembling the gear become too complicated and increased, thus increasing the costs problematically.
Also, in detection of the position of the roof panel, for example, when the full-closed position is detected in a series of operations performed in the order of tilting-up, tilting-down, full-opening, full-closing, and tilting-up, the state where the roof panel stays in a full-closed state lasts only short as compared to the total travel of the roof panel driving cable. That is, in that state, the rotation angle of the driving device is very small when it is engaging with the cable, much less is the rotation angle of the drunken gear while it is decelerating that.
Although, on the other hand, deceleration by the drunken gear can be made efficient, when a predetermined rotation angle of the dependent member after being decelerated is to be detected, that rotation angle, even if it is small, is a wide one as the rotation angle of the output shaft before it is decelerated. To permit the output shaft to rotate by a wide angle, however, the range must be larger for detecting the full-closed position, thus enlarging and complicating the device.
Further, in the case of the opening/closing driving device having such a configuration, as a manual operation for emergency, and the like, only the output shaft side is rotated with the clutch mechanism to limit the rotation of the worm wheel gear. That is, the clutch mechanism is disposed between the worm wheel gear and the output shaft side, to limit by that much the position of providing the panel-position detecting means, thus giving rise to many restrictions in layout problematically.
Also, the panel-position detection means must often be arranged opposite the clutch mechanism with the body housing therebetween, in which case the clutch mechanism and the panel-position detecting means are assembled on the opposite side with the housing therebetween. Therefore, those components cannot be assembled as stacked one on the other in the same direction, thus deteriorating the workability of assembly problematically.
It is an object of the present invention to provide a small-sized sunroof driving device which has a small projection area and good assembling easiness.
It is another object of the present invention to improve the accuracy of detecting the roof panel position in such a sunroof driving device.
It is further another object of the present invention to provide a sunroof driving device which has a high degree of freedom in layout of its components and good assembling easiness, thus being easily applicable to various specifications.
The sunroof driving device according to the present invention is a sunroof driving device which comprises a motor, a worm gear provided on the armature shaft of said motor, a worm wheel gear which meshes with said worm gear, an output shaft coupled with said worm wheel gear, and a drive output section which is provided on said output shaft and which meshes with a wire for driving the roof panel for opening/closing an opening in the roof of a vehicle, characterized in that on the same axis with said output shaft are disposed a panel position detecting means for detecting the position of said roof panel and a manual operation section for driving said roof panel manually.
According to the present invention, the output shaft, the panel position detecting means, and the manual operation section are disposed on the same axis, to enable efficient and compact mounting of the panel position detecting means, the manual operation section, and the like. With this, the device has a smaller projection area and so can be miniaturized. Also, as those components are disposed on the same axis, each part can be stacked one on another in assembly, thus improving assembling easiness.
Also, said manual operation section may be formed on the main shaft of said panel position detecting means coupled with said output shaft, to thus enable assembling also the manual operation section only by attaching said panel position detecting means.
Further, said worm gear and worm wheel gear may be configured so that said armature shaft may be slid from the side of said output shaft. That is, the worm side may be driven from the wheel side by adjusting the lead angle and the friction angle of the worm wheel gear and the worm gear. With this, the clutch can be eliminated between the worm wheel gear and the output shaft, thus maintaining a correlation in terms of rotation angle between the output shaft and the armature shaft.
In addition, the sunroof driving device according to the present invention is characterized in that said panel position detecting means thereof includes a first dependent member which rotates integrally with said output shaft, a second dependent member which rotates when a rotation of said output shaft is decelerated and transmitted thereto, and a signal generating means which outputs a signal only when two rotational-position detecting sections respectively provided on said first and second dependent members come at a same position.
Thereby, the first dependent member with a higher rotation speed can be used to regulate an output time for the signal output from the signal generating means based on operations of the second dependent member with a lower rotation speed, thus setting the signal output time more accurately than a case using the second dependent member alone. Therefore, the accuracy can be improved of the detection signal indicating the position of the roof panel, thus sensing the current position of the roof panel more accurately.
Further, the sunroof driving device according to the present invention comprises a motor, a worm gear provided on an armature shaft of said motor, a worm wheel gear meshing with said worm gear, an output shaft coupled with said worm wheel gear, and a drive output section which is provided on said output shaft and which meshes with a wire driving a roof panel for opening/closing an opening in the roof of a vehicle, characterized in that it further has a body-side manual operation section provided on said output shaft for driving said roof panel manually, a panel-position detecting means formed as an independent unit for detecting the position of said roof panel, and a unit-side manual operation section which is disposed in said panel-position detecting means and interlocked with said body-side manual operation section to thereby enable manual sliding of said roof panel.
According to the present invention, the panel-position detecting means is formed as an independent section and there is provided the unit-side manual operation section interlocking with the body-side manual operation section provided on the output shaft, so that only by mounting the panel-position detecting means on the gear body, provisions for manual operation can be disposed on the driving device. Also, the panel-position detecting means is formed as a unit and, at the same time, the body-side manual operation section is provided on the output shaft, so that by attaching and detaching the panel-position detecting means, the driving device can easily accommodate such specifications that need no detection of the panel position, thus reducing the man-hour requirements in design and sharing the number of parts.
On the other hand, the panel-position detecting means and the output shaft may be formed detachable, to thereby improve the assembly performance of the panel-position detecting means further.